So the only problem with the rock thing is time - You'd have the same exact GOD and the same exact rock and the only diffrece be time. at time 1 GOD creates the rock and at time 2 He is able to lift the previously unliftable rock. I dunno, you wanted logic.

Why doesn't God just make himself unable to lift the rock? Sure, he wouldn't be omnipotent anymore. But who said he had to be? The whole "Eternal and unchanging" thing? That broke apart within the second infinitesimally small moment after the universe was "created".

Not a bad answer, for a ten-year-old. But it can be immediately dodged by wearily clipping "at that moment" on the end of the question. An omnipotent being would be outside of our primative space-and-time bungalow, and wouldn't need to squeeze out of the way to avoid so-called paradoxes. He created matter out of nothing, so he can easily lift an unliftable thing, even if the thing is unliftable to him. As contradictions within your worldviews go, this is the least of your worries.